Hunt P R, Aggleton J P
Medical Research Council Cambridge Centre for Brain Repair, University of Cambridge, Cambridge, CB2 2PY, United Kingdom.
J Neurosci. 1998 Dec 1;18(23):10045-52. doi: 10.1523/JNEUROSCI.18-23-10045.1998.
This study examined the acquisition of a T-maze matching to place task by rats with neurotoxic lesions of the thalamic nucleus medialis dorsalis. This test of spatial working memory also entails learning a task rule that is contrary to the animals' innate preference. The rats next performed the same matching task over different retention delays. Finally, they were trained on a reversal of the task rule, i.e., to nonmatch to place. Although the lesions produced a clear acquisition impairment on the matching task, there was no evidence of a loss of working memory. A series of control tasks found no appreciable effect on a conditioned cue preference task or on open field activity. The pattern of results shows that medialis dorsalis lesions lead to a selective increase in perseverative behavior that can retard task acquisition. This perseverative deficit closely resembles that observed after prefrontal damage in rats, strongly indicating dysfunction in a common system.
本研究检测了丘脑背内侧核发生神经毒性损伤的大鼠对T形迷宫位置匹配任务的习得情况。这项空间工作记忆测试还需要学习与动物先天偏好相反的任务规则。接下来，大鼠在不同的保持延迟条件下执行相同的匹配任务。最后，它们接受任务规则反转训练，即位置不匹配训练。尽管损伤在匹配任务中产生了明显的习得障碍，但没有证据表明工作记忆丧失。一系列对照任务发现，对条件性线索偏好任务或旷场活动没有明显影响。结果模式表明，背内侧核损伤导致持续性行为选择性增加，从而可能阻碍任务习得。这种持续性缺陷与大鼠前额叶损伤后观察到的缺陷非常相似，强烈表明一个共同系统存在功能障碍。
